Occlusion of arterial blood supply to various body parts can cause severe damage to vital structures, especially if the occlusion includes a large vessel, happened acutely or subacutely, and/or was prolonged. The main reason for organ or extremity damage is the lack of oxygen supply as well as other nutrients delivered by the arterial high pressure blood stream. With a stroke, for example, there is a rapidly developing loss of brain function due to a disturbance in the blood vessels supplying blood to the brain. Studies have shown that millions of brain cells die each minute following initial loss of blood flow to the brain.
Various techniques are known for reperfusing the occluded arterial supply, including direct mechanical reperfusion (balloon or dilator), elimination of occlusion (embolectomy or resection/anastomosis), bypassing the occlusion (CABG), reopening the occlusion (stent), pharmacologic dissolution (TPA for fibrinolysis, Heparin, Aspirin), etc. Each of these methods, has advantages and disadvantages. However, little progress has been observed where the occluded arterial supply is in a sensitive and surgically challenging location and the affected body part is irreversibly damaged in a short period, for example with a stroke. A thrombotic or embolic stroke can range from being totally asymptomatic to death. Large strokes tend to leave sever neurological deficits in the sensory and/or motor systems.
The pharmacologic treatment for a stroke, for example, is not as successful as in the case of the cardiac muscle. The use of fibrinolytic agents, namely TPA, should be achieved within a three hour window from incidence. There is also heightened risk of cerebral arterial or parenchymal bleeding that does not exist in the case of coronary reperfusion by TPA. The location and anatomy of the cerebral blood vessels make them more challenging to mechanical reperfusion by catheters, balloons, and/or stents. Surgical trials at embolectomy are tried in the case of large occlusion of a proximal cerebral blood vessel. Results are inconsistent due to the rapidity of brain cell injury and the irreversibility of their viable functions. The only networks of capillaries vasculature supplying the neuronal structures other than the arterial network include the venous and the lymphatic networks. Blood flows from the arterial side to small arteries named arterioles to end in a fine capillary network that supplies the tissues on cellular microscopic level. On the same level of capillaries, the venous network forms to collect venous blood and form bigger vessels named venules that eventually coalesce to form the cerebral veins. The lymphatic capillary network runs parallel to the venous system in general plus extra fluid system represented by the CSF circulation through specialized tissues surrounding the brain.
Accordingly, there remains a need for methods and devices for temporarily or permanently restoring oxygenated blood supply to affected body parts.